Tiktaalik roseae—a fishy ‘missing link’

15 April 2006

The secularized mainstream media (MSM) are gleefully
promoting a recent find, Tiktaalik roseae (right), as the end of any creationist
or intelligent design idea. Some paleontologists are claiming that this is ‘a
link between fishes and land vertebrates that might in time become as much of an
evolutionary icon as the proto-bird Archaeopteryx.’1

So is Tiktaalik real evidence that fish evolved into tetrapods (four-limbed
vertebrates, i.e. amphibians, reptiles, mammals and birds)? As will be shown, there
are parallels with Archaeopteryx,
the famous alleged reptile-bird intermediate, but not in the way the above quote
claims!

What was found?

The above quote comes from two leading European experts in the alleged evolutionary
transition from fish–tetrapod, Per Ahlberg and Jennifer Clack. It was about
the find of well-known American leaders on the same alleged transition, Neil Shubin
and Edward Daeschler, and which was the cover story for Nature.2,3
Clack, Shubin and Daeschler even previously featured on the PBS-Nova seven-part
series, Evolution, Episode 2: Great Transformations
about the origin of tetrapods.

Shubin et al. found a 20-cm-long skull sticking out of a cliff. They found
that this skull, superficially like a crocodile’s, was part of a fish that
had a fin that was supposedly on the way to becoming a tetrapod limb. They ‘dated’ it to 383 Ma (million years ago).
Since it was in Ellesmere Island, Nunavut Territory (Canada), it was given a genus
name from the indigenous Inuktitut word for burbot, or large, shallow freshwater
fish.

Is it transitional?

Clack and others are naturally enthusiastic about Tiktaalik’s transitional
status. But this is not surprising—to her, we are all fishes anyway! She states:

‘Although humans do not usually think of themselves as fishes, they nonetheless
share several fundamental characters that unite them inextricably with their relatives
among the fishes … Tetrapods did not evolve from sarcopterygians
[lobe-finned fishes]; they are sarcopterygians, just as one would not say
that humans evolved from mammals; they are mammals.’4

This is reminiscent of University of Kansas paleontologist Larry Martin criticising
overly enthusiastic ‘feathered dinosaur’ claims:

‘You have to put this into perspective. To the people who wrote the paper,
the chicken would be a feathered dinosaur.’5

Clack also admitted:

‘There remains a large morphological gap between them and digits as seen in,
for example, Acanthostega: if the digits evolved from these distal bones,
the process must have involved considerable developmental repatterning. …

‘Of course, there are still major gaps in the fossil record. In particular
we have almost no information about the step between Tiktaalik and the
earliest tetrapods, when the anatomy underwent the most drastic changes, or about
what happened in the following Early Carboniferous period, after the end of the
Devonian, when tetrapods became fully terrestrial.’1

Indeed, the evolution of land limbs and life on land in general requires many changes,
and the fossil record has no evidence of such changes. Geologist Paul Garner
writes:

‘[T]here are functional challenges to Darwinian interpretations. For instance,
in fish the head, shoulder girdle, and circulatory systems constitute a single mechanical
unit. The shoulder girdle is firmly connected to the vertebral column and is an
anchor for the muscles involved in lateral undulation of the body, mouth opening,
heart contractions, and timing of the blood circulation through the gills.6 However, in amphibians
the head is not connected to the shoulder girdle, in order to allow effective terrestrial
feeding and locomotion. Evolutionists must suppose that the head became incrementally
detached from the shoulder girdle, in a step-wise fashion, with functional intermediates
at every stage. However, a satisfactory account of how this might have happened
has never been given.’

Indeed, Tiktaalik’s fin was not connected to the main skeleton, so
could not have supported its weight on land. The discoverers claim that this could
have helped to prop up the body as the fish moved along a water bottom,3
but evolutionists had similar high hopes for the coelacanth fin. However, when a
living coelacanth (Latimeria chalumnae) was discovered in 1938, the fins
turned out not to be used for walking but for deft manœuvering when swimming.

Transitional limb?

Quite aside from the huge problems explaining the origin of locomotion, there are
other problems. The series of corresponding limbs (Fig. 2, right) does not
appear to show the clear progression. Even from looking at it, it is not obvious
that the Panderichthys limb belongs in between the adjacent ones in the
series. It has fewer small bones. The authors themselves appear to recognize this:

‘In some features, Tiktaalik is similar
to rhizodontids such as Sauripterus. These similarities, which are probably
homoplastic, include the shape and number of radial articulations on the ulnare,
the presence of extensive and branched endochondral radials, and the retention of
unjointed lepidotrichia.’

‘Homoplastic’ essentially means ‘convergent’ or ‘analogous’,
i.e. independently evolved because of a common function (such as the wings of pterosaurs,
bats, birds and insects, according to evolutionists), rather than evolved from a
common ancestor (homologous, as evolutionists claim for features such as the different
forelimbs here). But homology
is alleged to be the evidence for evolution (despite many problems—see
Common structures = common ancestry?) But appeal to homoplasy is really
explaining away evidence that doesn’t fit the paradigm, and indeed
such explaining away is ubiquitous. Two evolutionists admit:

‘Disagreements about the probable homologous or homoplastic nature of shared
derived similarities between taxa lie at the core of most conflicting phylogenetic
hypotheses.’7

In fact, when more characteristics than just one are analysed, homoplasies become
even more necessary to explain away anomalies, as will be explained in the section
Mosaic rather than transitional.

Another major problem is that evolutionists appeal to the common pentadactyl 5-digit
pattern as evidence for their common ancestry from a 5-digited creature. Yet the
nearest creatures they have to a common ancestor did not have five digits! Acanthostega
had eight, while Ichthyostega had seven.

Fossil order

Fig. 3 (right) does much to popularize evolution, but there are a number of problems.

The caption admits, ‘These drawings are not to scale, but all animals are
between 75 cm and 1.5 m in length.’ If size were taken into account, would
there be such a clear progression? Compare a far more extreme example, the
supposed land-mammal–to–whale sequence.
This was also illustrated as equally sized, but Basilosaurus was 10 times
longer than Ambulocetus.

Another admission is, ‘The vertebral column of Panderichthys is poorly
known and not shown.’ We should remember the Pakicetus
fiasco: when a few bones were known, evolutionists drew it like a half-way
land-water form. But when more bones were found, it was realized that it was a fast-running
land mammal.

All the fossils of this entire series are assigned to middle-upper Devonian, or
385–365 Ma. Naturally, there are many problems with
dating , but even under the evolutionists’ own scenario, there are
problems. E.g. the entire fish-to-tetrapod transition is supposed to have occurred
in 20 Ma, but other salamanders, according to Shubin himself,
have remained unchanged for far longer :

‘Despite its Bathonian age, the new cryptobranchid [salamander] shows extraordinary
morphological similarity to its living relatives. This similarity underscores the
stasis [no change] within salamander anatomical evolution. Indeed, extant cryptobranchid
salamanders can be regarded as living fossils whose structures have remained little
changed for over 160 million years.’8

Even more importantly, the order is not right! Compare Fig. 4 (right): Panderichthys
is dated earlier than its supposed predecessor, Eusthenopteron. And all
are earlier than the undoubted fish, the coelacanth. This is yet another parallel
with alleged bird evolution—undoubted beaked
birds like Confuciusornis are 10 Ma older than their alleged feathered
dinosaur ‘ancestors’. Evolutionists would argue that it is not
a problem, for the same reason that sometimes a grandfather can outlive his grandson.
This is correct, but one of the major ‘evidences’ of evolution is how
the evolutionary order supposedly matches the fossil sequence. So the mismatch of
claimed order of appearance with claimed phylogeny undermines the evolutionary explanation.

Also, Acanthostega is allegedly a predecessor to Ichthyostega,
but they were actually contemporaries.

Mosaic rather than transitional

Many of the alleged transitional forms do not have structures in transition from
one form to another. Rather, the alleged transitional nature is a combination of
fully-formed structures that in themselves are not transitional.9

Also, who was the predecessor of whom in the case of Acanthostega and Ichthyostega?
It depends on which characteristic one looks at: e.g. Ichthyostega's
skull seems more fish-like than Acanthostega’s, but its shoulder
and hips are more robust and land-animal–like.10

‘The same sort of reasoning and logic as was used in this article would apply
to the fish-to-tetrapod series. In this proposed reptile-to-mammal series, features
do not progress consistently. Some organisms towards the mammal end of the series
are devoid of certain mammal-like features present in organisms closer to the reptile
end of the series. The majority of the hundred-odd traits examined did not progress
consistently.’

Rather, it supports a particular subset of ID: the biotic message theory,
as proposed by Walter ReMine in The Biotic Message. That is, the evidence from nature
points to a single designer, but with a pattern which thwarts evolutionary
explanations. In this case, the common modules point to one common designer,
but evolution is powerless to explain this modular pattern, since natural selection
can work only on organisms as a whole. That is, it cannot select for particular
head design as such, but only for creatures that have a head that confers
superior fitness. But a designer who worked with different modules could create
different creatures with different modules, that fit no consistent evolutionary
pattern.

Gudo, M. and Homberger, D.G., Functional morphology
of the coracoid bar of the Spiny Dogfish (Squalas acanthias): implications
for the evolutionary history of the shoulder girdle of vertebrates, 43rd Annual
Meeting of the Palaeontological Association, Manchester, 19–22 December
1999; <www.palass.org/index.html>, 4 April 2003. Click on ‘Abstracts’
then ‘Manchester 1999’. Return to text.

The great commission tells us to preach the Gospel to every nation. We might not be able to go there in the flesh but this site can penetrate every country on the globe. Help the world find 'creation'. Support this site